There exist primary or secondary cells having positive and negative electrodes as Li-accumulators, zinc-air cells or lithium-air cells or other types of cells or metal-air cells, which function according to an electrochemical principle. Primary cells are not rechargeable, while secondary cells are rechargeable. Generally, some types of cells having metal electrodes contain metal as negative electrodes, which following the discharge are used up by a chemical reaction. In this case, the metal in the chamber of the negative electrode is converted into a chemical product, usually an ion, which enters an electrochemical reaction at the positive electrode, the so-called cathode. This occurs under the influence of another chemical element such as sulfur, oxygen or another material such as a metal oxide, for example lithium cobalt or other oxide mixtures of lithium, nickel, manganese and/or cobalt.
Cells that have no intercalation reactions, such as lithium-air cells or lithium-sulfur cells, form a chemical reaction product following the discharge of the cell. This reaction product may be formed:    A) outside of conductive fibers or grains, i.e. on the surface of conductive carbon structures or coated (e.g. TiC-coated) conductive structures; or it may be formed within electroactive structures    B) such as sulfurized polyacrylic nitrile grains or fibers in the case of a sulfur-polyacrylic nitrile cathode of a lithium-sulfur cell according to the related art.
Structures A and B are exposed to a solid or liquid electrolyte, which connects the cathode space with the anode space in an ion-conductive manner via a separator.
Patent document WO 03/012908 A2 discusses electrode materials that have interpenetrating structures in order to ensure fast transport paths both for electrons as well as for lithium ions. The interpenetrating structures may have a varying topology or morphology.
In Heon-Cheol Shin et al., Journal of Power Sources 2005, 139, 314-320, are discussed porous negative electrodes for rechargeable lithium batteries. The Journal discusses the differences of the charge transport in different ratios of pore depth and diameter.
Patent document US 2013/0143115 A1 discuss three-dimensional porous electrode materials for lithium-ion batteries. The document mentions that the diffusion path of the lithium ions is shortened by a porous structure of the electrode material.